Ironically, you said that to call it a curse takes the power out of the filmmakers' hands, which is actually part of the problem.

What I meant by that was that a 3rd entry would inevitably end up being panned, no matter the effort put forth by the creative team, so they're powerless and it would be pointless to embark on making a 3rd film. I don't agree with that because it implies that it is impossible to solve 3rd entry problems.

What I think you're referring to is studio tampering in the 3rd entry, am I right?

If so, I think that could come with the territory, especially with blockbuster series. I think that the story problems that will likely arise in 3rd entries could create a level of friction between the creative team and the studio about what is best for the film. If that's the case, then I think the 2nd paragraph in the "In the future..." section of my first post could be applied as a solution.